NEW YORK (Reuters) – A high volume of holiday packages overwhelmed shipping and logistics company UPS, the company said on Wednesday, delaying the arrival of Christmas presents around the globe and sending angry consumers to social media to vent.

A convergence of factors, including higher volume than expected and recent patches of bad weather, caused the delays, UPS spokeswoman Natalie Black said.

The company projected 132 million deliveries last week “and obviously we exceeded that,” Black said, without disclosing how many packages had been sent.

“For now, UPS is really focused on delivering the remaining packages,” Black said. “You might not see trucks, but people are working.”

Customers awaiting deliveries should expect packages on Thursday or Friday and those with delivery guarantees will get appropriate refunds, she said. Amazon.com’s email said credits were applied directly to user accounts.

Packages shipped via UPS for Amazon.com by Prime customers, who pay $79 a year for two-day shipping, may be eligible for additional refunds. Amazon’s stated policy for missed deliveries is to offer a free one-month extension of Prime.

UPS has not yet coordinated with Amazon, nor has it determined what percentage of the undelivered packages were from Amazon, Black said.

Amazon also did not disclose how many of its shipments were affected or how many users got the email about delayed orders.

“If customers from Amazon were impacted, we’ll work with Amazon to resolve that,” Black said.

Amazon processed customer orders on time for holiday delivery, company spokeswoman Mary Osako said. “We are reviewing the performance of the delivery carriers,” she said.

Frustrated consumers took to social media, with some complaining that gifts purchased for their children would not arrive in time to make it under the tree by Christmas morning.

“Really @UPS would have been better had you delivered our package yesterday like it was scheduled,” tweeted a user named Heather Bender, who added the hashtags #UPSFail and #NoSantaGiftForMySon.

“Package was delayed in transit & not received as guaranteed. Disappointed 9 year old,” said a Twitter user named Jennifer Marten.

Others on social media urged shoppers to be more appreciative of the delivery company’s work during the holiday season.

“While others take vacation and time off in December, remember we aren’t allowed ever to be off in December. Ever,” Donny Ratcliffe, who identified himself as a UPS driver for the last 20 years, said on the UPS Facebook page.

“So when you see your family and complain that your package is held up, everyone who moves your package is working and doesn’t get the Xmas experience you get,” he said. “Be thankful for that.”